Search

Fertilizer phosphorus (P) is a finite resource, necessitating the development of innovative solutions for P fertilizer efficiency in agricultural systems. Myo-inositol hexakisphosphate (phytate) constitutes the majority of identified organic P in many soil types and is poorly available to plants. Incorporating phytase-producing biofertilizers into soil presents a viable and environmentally acceptable way of utilizing P from phytate, while reducing the need for mineral P application. A deeper understanding of the microbial ecology in relation to degradation of phytate under natural soil conditions is however needed to obtain successful biofertilizer candidates able to compete in complex soil environments. Here we present the development of a microcosm for studying microbial communities able to colonize and utilize Ca-phytate hotspots in solum. Our results provide evidence that the recruited microbial population mineralizes Ca-phytate. Furthermore, quantification of bacterial genes associated with organic P cycling in alkaline soils indicated that the phosphatases PhoX and PhoD may play a larger role in phytate mineralization in soil than previously recognized. Amplicon sequencing and BioLog® catabolism studies show that hotspots containing Ca-phytate, recruited a different set of microorganisms when compared to those containing an addition of C source alone, with the genus Streptomyces specifically enriched. We propose that Streptomyces represents an hitherto unexplored resource as P biofertilizer with competitive advantage for utilizing CaPhy in an inherently competitive soil environment. We further conclude that the use of our newly designed microcosm presents an innovative approach for isolating soil microorganisms with the potential to degrade precipitated phytate in solum.

In ruminants, high fermentation capacity is necessary to develop more efficient ruminant production systems. Greater level of production depends on the ability of the microbial ecosystem to convert organic matter into precursors of milk and meat. This has led to increased interest by animal nutritionists, biochemists and microbiologists in evaluating different strategies to manipulate the rumen biota to improve animal performance, production efficiency and animal health. One of such strategies is the use of natural feed additives such as single-celled fungi yeast. The main objectives of using yeasts as natural additives in ruminant diets include; (i) to prevent rumen microflora disorders, (ii) to improve and sustain higher production of milk and meat, (iii) to reduce rumen acidosis and bloat which adversely affect animal health and performance, (iv) to decrease the risk of ruminant-associated human pathogens and (v) to reduce the excretion of nitrogenous-based compounds, carbon dioxide and methane. Yeast, a natural feed additive, has the potential to enhance feed degradation by increasing the concentration of volatile fatty acids during fermentation processes. In addition, microbial growth in the rumen is enhanced in the presence of yeast leading to the delivery of a greater amount of microbial protein to the duodenum and high nitrogen retention. Single-celled fungi yeast has demonstrated its ability to increase fibre digestibility and lower faecal output of organic matter due to improved digestion of organic matter, which subsequently improves animal productivity. Yeast also has the ability to alter the fermentation process in the rumen in a way that reduces methane formation. Furthermore, yeast inclusion in ruminant diets has been reported to decrease toxins absorption such as mycotoxins and promote epithelial cell integrity. This review article provides information on the impact of single-celled fungi yeast as a feed supplement on ruminal microbiota and its function to improve the health and productive longevity of ruminants.

The production of livestock and poultry faces major challenges to meet the global demand for meat and dairy products and eggs due to a steady increase in the world's population and the ban of antibiotics in animal production. This ban has forced animal nutritionists to seek for natural alternatives to antibiotics. In this context, the yeast Saccharomyces cerevisiae has received considerable attention in the last decade. It has been reported that feed supplementation with live yeast cells improve feed efficiency, enhance feed digestibility, increase animal performance, reduce the number of pathogenic bacteria, improve animal health and reduce the negative environmental impacts of livestock production. The current review sheds light on the effects of the use of live Saccharomyces cerevisiae cells in the diets of non-ruminant and pseudo-ruminant's animals and the mechanisms by which they exert its effects. This review work revealed that the addition of Saccharomyces cerevisiae in poultry feed causes a phenomenon called competitive exclusion of pathogenic bacteria capable of causing disease adhere to the yeast surface, and so removing a large amount of harmful microorganisms and allowing the Animal defend more effectively, the production of antimicrobial agents, the balancing the gut microbiota and stimulation of host adaptive immune system and improving gut morphological structure, thus these benefits are reflected on the overall poultry health. In addition, in the presence of live Saccharomyces cerevisiae cells, the immunity of rabbits was improved due to the high number of white blood cell. In addition, apparent digestibility of acid and neutral detergent fiber was improved in horses and rabbits. Saccharomyces cerevisiae in pig diets augment mucosal immunity by increasing IgM and IgA activity against pathogens, enhance intestinal development and function, adsorb mycotoxins, modulate gut microbiota and reduce post-weaning diarrhea. This article is protected by copyright. All rights reserved.

Aims Isolation and identification of genes encoding putative phosphatases from Pseudomonas putida strain P13 DSM 23335. Methods and results By functional screening of a P. putida P13 genomic library, a number of Pho+ clones were identified. Two genes were identified that encoded proteins exhibiting both phytase and sugar phosphatase activities. The proteins were 249 and 462 amino acids, with molecular masses of 26 and 50 kDa respectively. Sequence alignments revealed no significant similarities to representatives of known phosphatase or phytase gene families. However, the genes were found to have a high similarity to members of the major facilitator superfamily (MFS). Both genes were overexpressed in Escherichia coli and the corresponding partially purified recombinant enzymes were found to have significant phytate-dephosphorylating activity. The protein designated P. putida phytase 1 (Ppp1) displayed the highest activity among potential substrates studied on Na phytate, whereas Ppp2 more likely represents a sugar phosphatase than a phytase. The optimal conditions for phytate dephosphorylation were determined as 60°C and pH 4·5 (Ppp1) or pH 5·0 (Ppp2). Conclusions Two novel bacterial phosphatase-encoding genes, named ppp1 and ppp2, were isolated from P. putida P13 DSM 23335 by a functional screening procedure. Significance and impact of the study Phosphatase-encoding genes are of great importance for industrial applications, particularly in agriculture. The identified phosphatase genes represent a new class of acid phosphatases.

Background The study aims to investigate the limitation of a poultry digestive tract model developed by Menezes-Blackburn et al. [J Agric Food Chem 63: 6142-6149 (2015)] on the evaluation of the bioefficacy of phytases. Results It was confirmed that the in vitro model does not mimic the in vivo situation in the birds sufficiently well to identify the best phytase product under real conditions, or to draw conclusion on the effect of phytate concentration, phytate source or feed composition on the bioefficacy of phytase. Addition of calcium ion (Ca2+ ) up to a concentration of 10 g kg-1 to the feed substrate, for example, did not affect enzymatic phytate dephosphorylation in the in vitro model in contrast to the observation in poultry. Conclusion The in vitro approach was shown to be applicable as a complementary tool in the pre-selection of promising phytase candidates, resulting in a reduction in the number of feeding trials in the initial screening phase. © 2020 The Author. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

The present study explored the effect of garlic and/or eucalypt oils on biogas production during in vitro ruminal fermentation of four agro industry byproducts. For this, 0-180 mg oil L-1 incubation medium was added and gas volumes were recorded from 2 to 48 h of incubation. Dry matter substrate degradability and neutral as well as acid detergent fibre were determined after 72 h.; Results: Gas production and nutrient degradability was oil type dependent. The oils enhanced (P

The effect of phytase supplementation with respect to a high sorghum grain diet on sheep voluntary feed intake, apparent nutrient digestibility, ruminal fermentation, phosphorus (P) excretion and blood serum P concentration was evaluated.; Results: Phytase supplementation significantly decreased fecal P excretion (P = 0.003), resulting in a 26% decrease in relation to the phytase free diet. Dry matter intake, nutrient digestibility, ruminal butyrate and serum P were not (P > 0.10) affected by the phytase level. Neutral detergent digestibility showed a tendency to increase linearly (P = 0.10) with increasing phytase levels. Ruminal pH was lower for phytase supplemented sheep, with a significant decrease (P = 0.007) at 9 h post feeding, whereas ruminal ammonia-N at 3 h post feeding was lower (P = 0.004) for the phytase treatment groups, resulting in a decreasing linear response (P = 0.001) with an increasing phytase dose. Duodenal pH was significantly reduced at 6 h post feeding. Propionate tended (P = 0.051) to be increased linearly as the phytase supplementation level increased.; Conclusion: Exogenous phytase supplementation of high sorghum grain diets significantly decreased fecal P excretion in Rambouillet rams. Phytase supplementation appears to affect neutral detergent fiber digestibility, duodenal and ruminal pH, ammonia and propionate. © 2018 Society of Chemical Industry.; © 2018 Society of Chemical Industry.

Background Consumption of protein-based food products has a key role in the improvement of human health. The crosslinking agent microbial transglutaminase (mTGase) is an effective and promising tool to modify animal proteins used in the food industry. Improvement in the gelation process, physicochemical and textural quality, and consumer's demand of protein-based food products could be attained by combining mTGase and some non-conventional food processing technologies. Scope and approach New perspectives and key areas for future research in the development of high-quality food proteins and protein-based products as a function of interaction effect of mTGase and some new processing techniques (e.g. high pressure processing (HPP), ultrasound, microwave (MW) and ultraviolet (UV) irradiation) are reviewed. The effect of conventional thermal and emerging processing methods on the mTGase crosslinking activity and protein gel functionality are also compared. Key findings and conclusions The crosslinking density and functional properties of protein gels can be strongly promoted by the synergistic action of mTGase and innovative processing methods. Compared to the conventional heating, HPP with further increase of mTGase affinity to proteins can result in products with better physicochemical quality and more complex and firmer gel structure. The yield, water holding capacity, surface hydrophobicity, strength, and viscoelastic characteristics of mTGase-catalyzed protein gels can be significantly increased by ultrasonication treatments. mTGase-crosslinked hydrogels subjected to high-intensity ultrasonic pretreatment have potential to be used as delivery vehicles for a wide spectrum of bioactive compounds. The application of MW and UV light can substantially improve the surface, textural and structural features of gels generated by mTGase-technology.

The consumption of ready to eat vegetable salads among consumers in developing countries has increased with the change in life style pattern. However, food borne disease linked to these salads poses safety threats. Studies have shown the occurrence of various microbial pathogens which includes Escherichia coli, Listeria monocytogenes, coliforms , Salmonella etc. in these types of ready to eat vegetable salads. In order to overcome these safety threats, to control the microbial pathogens and to enhance the shelf life, different techniques like modified atmospheric conditions, refrigeration, innovative technologies etc. are exploited. This review insight on pathogenic prevalence of ready to eat vegetable salads in developing countries and technological advances used to counter these pathogens.

Phytases are a diverse group of enzymes initiating the dephosphorylation of phytate. Phytate is considered as an anti-nutritional compound because of its capability to chelate nutrients such as Fe2+ , Zn2+ , Mg2+ , and Ca2+ . In this study, several bacterial isolates obtained from earthworm casts were evaluated for their phytate degrading capability. Enzymatic properties and the sequence of the corresponding phytase-encoding gene of the selected isolate were determined.; Results: The phytase exhibited its highest activity at pH 4.0 and was stable from pH 3 up to pH 9. The temperature optimum was determined to be 65 °C. The strongest inhibitors of enzymatic activity were identified as vanadate, Cu2+ , and Zn2+ . High-performance ion chromatography analysis of enzymatic phytate dephosphorylation revealed that the first dephosphorylation product was d/l-myo-inositol(1,2,3,4,5)pentakisphosphate.; Conclusion: Owing to its enzymatic properties, such as tolerance to tartrate and the presence of the consensus motifs PDTVY, GNHE, DLG, VLFH, and GHDH, this phytase could be classified as a purple acid phytase. To the best of our knowledge, this is the first report describing a bacterial purple acid phytase. © 2017 Society of Chemical Industry.; © 2017 Society of Chemical Industry.

Small plastic particles are found ubiquitously in marine and freshwater ecosystems and consequently, their inhabitants. When aquatic animals are consumed as seafood, human exposure to those plastic particles is possible. However, only a few studies, applying largely different analytical procedures, assessed microplastics content in the edible part of seafood. In this study, ten protocols for the extraction of microplastics from biota were chosen and tested for their suitability to digest the edible part of a broad range of seafood species. The following criteria were used for this assessment: 1) feasibility to filtrate the entire digested sample with one filter of approximately 1 μm pore size, 2) effect of reagents applied during the sample preparation on the polymer integrity as assessed by means of infrared and Raman spectroscopy as well as pyrolysis gas chromatography mass spectrometry, 3) total sample preparation time and the possibility to avoid the use of expensive reagents. The most suitable protocol was found to be an enzymatic-alkaline approach, consisting of a quick hydrolysis of proteins with pepsin for 2 h and a consecutive alkaline hydrolysis for 4 h, both at 37 °C for most of the tested seafood species. Digestion efficiency of the optimised protocol was tested with fish fillets and soft tissues of commercially relevant molluscs and crustacean species. Compared to most other protocols described in literature, an adequate digestion of the seafood matrix was achieved faster without being significantly more cost- or labour-intensive. Moreover, only negligible degradation of eleven commercially relevant polymers excluding polyacrylonitrile was observed. Polymer integrity was assessed by a change in particle weight or surface as well as spectroscopic and chromatographic data. The optimised sample preparation protocol aims to support future method standardisation efforts in order to assess the dietary uptake of microplastics in humans.

The objective of the present study was to determine the shelf-life of minimally-processed fresh-cut apples treated with anti-browning agents under modified atmosphere packaging. Shelf-life is calculated by application of mathematical models with product quality attributes such as: pH; soluble solids content (SSC); CIELab color parameters; sensory evaluation; and microbial spoilage (Salmonella spp., Staphylococcus aureus, Sulfite-Reducing Clostridium, Enterobacteriacae, Escherichia coli, Aerobic mesophilic bacteria (AMB), yeast, mold, Listeria monocytogenes). Golden Delicious and Cripps Pink apple cultivars were individually treated with one of several anti-browning treatments and packaged in a modified atmosphere (N2 = 90.5%; CO2 = 2.5%; O2 = 7%), and stored at 4 °C. The treatments were; 1) non-treated (control); 2) dipping in a mixture of ascorbic and citric acids for 3 min with and without ultrasound (40 kHz, 3 min) treatment; and 3) Ca-ascorbate with/without ultrasound (40 kHz, 3 min) treatment. Results revealed that Cripps Pink was the most suitable variety for minimally-processed fresh-cut product. All the investigated treatments were equally effective in improving the quality of the product compared to the control. Shelf-life predictive models were developed based on the following quality attributes: apple cultivar, anti-browning treatment, color parameters, sensory evaluation, pH, and SSC. Maximum growth rates for Enterobacteriacae and Aerobic mesophilic bacteria were 0.25 ± 0.02 log CFU/g/day and 0.46 ± 0.02 log CFU/g/day, respectively. In order to optimize fresh-cut production, these models can be useful tool for predicting the longest shelf-life time with monitoring microbial activity during production. All models are freely available on-line (“Anti-browning Apple Calculator – C.A.P.P.A.B.L.E.©”; apple.pbf.hr or 31.147.204.87).

It is of utmost importance, that reliable exposure data about the migration behavior of nanoparticles are collected in order to provide adequate information for the safety assessment of engineered nanoparticles (ENPs) used in the food packaging sector. The objective of this study was to evaluate the migration behavior of silver nanoparticles (AgNPs) from model food packaging films with varying nanosilver content into three different food simulants (water, 10% ethanol and 3% acetic acid). The overall silver migration determined by classical inductively coupled plasma mass spectrometry (ICP-MS) analysis was dependent on the silver content of the films, the food simulant used and the contact time and temperature applied. Furthermore, single particle ICP-MS analysis was applied in order to detect and quantify migrated AgNPs selectively. As coexistent silver ions in the migration samples had an impedient effect (decreased signal-to-noise ratio), an optimized analytical approach was developed by online-coupling of asymmetric flow field flow fractionation (AF 4 ) to single particle-ICP-MS. The enrichment of the nanoparticle fraction and simultaneous reduction of the ionic background via AF 4 resulted in a clearly improved ICP-MS detection sensitivity, which enabled a more refined identification and size characterization of the migrated silver species. Scanning transmission electron microscopy (STEM) and energy-dispersive x-ray spectroscopy (EDS) confirmed independently the presence of AgNPs and silver/polymer heteroaggregates in the migration samples.

International audience; Edible seaweeds are a good source of antioxidants, dietary fibers, essential amino acids, vitamins, phytochemicals, polyunsaturated fatty acids, and minerals. Many studies have evaluated the gelling, thickening and therapeutic properties of seaweeds when they are used individually. This review gives an overview on the nutritional, textural, sensorial, and health-related properties of food products enriched with seaweeds and seaweed extracts. The effect of seaweed incorporation on properties of meat, fish, bakery, and other food products were highlighted in depth. Moreover, the positive effects of foods enriched with seaweeds and seaweed extracts on different lifestyle diseases such as obesity, dyslipidemia, hypertension, and diabetes were also discussed. The results of the studies demonstrated that the addition of seaweeds, in powder or extract form, can improve the nutritional and textural properties of food products. Additionally, low-fat products with less calories and less saturated fatty acids can be prepared using seaweeds. Moreover, the addition of seaweeds also affected the health properties of food products. The results of these studies demonstrated that the health value, shelf-life and overall quality of foods can be improved through the addition of either seaweeds or seaweed extracts.

Beans, peas, and lentils are all types of pulses that are extensively used as foods around the world due to their beneficial effects on human health including their low glycaemic index, cholesterol lowering effects, ability to decrease the risk of heart diseases and their protective effects against some cancers. These health benefits are a result of their components such as bioactive proteins, dietary fibre, slowly digested starches, minerals and vitamins, and bioactive compounds. Among these bioactive compounds, γ-aminobutyric acid (GABA), a non-proteinogenic amino acid with numerous reported health benefits (e.g. anti-diabetic and hypotensive effects, depression and anxiety reduction) is of particular interest. GABA is primarily synthesised in plant tissues by the decarboxylation of l-glutamic acid in the presence of glutamate decarboxylase (GAD). It is widely reported that during various processes including enzymatic treatment, gaseous treatment (e.g. with carbon dioxide), and fermentation (with lactic acid bacteria), GABA content increases in the plant matrix. The objective of this review paper is to highlight the current state of knowledge on the occurrence of GABA in pulses with special focus on mechanisms by which GABA levels are increased and the analytical extraction and estimation methods for this bioactive phytochemical. © 2017 Society of Chemical Industry.

Isolation and identification of temperature tolerant phosphate solubilizing bacteria (TTPSB) and their use as microbial fertilizers was the main goal of the study. In this study, TTPSB were isolated from soil samples treated for 16 h at 55 °C. Their phosphate solubilizing activity was either evaluated in solid media by forming a clear zone (halo) or in liquid media by quantification of the soluble phosphate in the growth medium. Five colonies (RPS4, RPS6, RPS7, RPS8 and RPS9) were identified to be able to form a halo and two of the isolates (RPS9 and RPS7) tolerated a temperature of 55 °C. With tricalcium phosphate (TCP) as the sole P-source, the phosphate solubilizing capacity of RPS9 and RPS7 was determined to be 563.8 and 324.1 mg P L−1 in liquid Sperber medium, respectively. Both bacterial isolates were identified as Pantoea agglomerans by molecular and biochemical characterization. To be used as a microbial fertilizer a carrier system for the temperature tolerant bacteria consisting of rock phosphate, sulfur and bagasse was used. It could be established that the bacterial cell counts of the microbial fertilizers were acceptable for application after storage for 4 months at 28 °C. In a greenhouse experiment using pot cultures, inoculation of maize (S.C.704) with the microbial fertilizers in an autoclaved soil resulted in a significant effect on total fresh and dry weight of the plant root and shoot as well as on the P content of the root and shoot. The effects observed with RPS9 as a component of the microbial fertilizer on plant growth and P nutrition was comparable with the addition of 50% of recommended triple superphosphate (TSP) dose. Using temperature tolerant bacteria in microbial fertilizers will overcome limitations in production and storage of the microbial fertilizers and contribute to a environmentally-friendly agriculture. The temperature tolerant P. agglomerans strain RPS9 was shown to be effective as part of a microbial fertilizer in supporting the growth and P uptake in maize.

Background Negative pressure cavitation (NPC) extraction is a novel effective and eco-friendly technology. In this method, cavitation is generated by negative pressure and continuously introduced into the liquid-solid system to enhance the turbulence, collision and mass transfer between the extracting solvent and solid matrix. This technique was found to be efficient for improving the substrate and enzyme mixing, increasing the enzymatic hydrolysis of the plant cell wall components and improving the intracellular contents release into the extraction solvent. Scope and approach So far, several studies evaluated the feasibility of using this system alone or in combination with other extraction methods (e.g. enzyme, homogenization, microwave, ionic liquid solvents and deep eutectic solvents) for extraction of food active compounds (e.g. flavonoids, isoflavonoids, saponins, stilbenes, polyphenols and alkaloids) from plant materials. This review gives an overview of the principle of NPC method and its application alone or in combination with other extraction techniques for extraction of active compounds from plant materials. Key findings and conclusions The outcome of the studies using NPC demonstrated that this technique is a simpler procedure, requiring low cost, and provides high efficiency. It is eco-friendly, and possesses a remarkable potential application in the industrial production compared to other extraction techniques. Moreover, since this method is performed at room temperature, it can reduce or prevent the degradation of thermosensitive compounds.

Because green biosynthesis using microorganisms is advertised as a promising, eco-friendly and biocompatible approach for the production of silver nanoparticles (AgNPs), many studies were focused on the extracellular production of nanoparticles enabling an easy downstream processing. However, the influence of the culture media on extracellular AgNP synthesis was rarely investigated. In this study, the effect of various culture media and their components on the extracellular AgNP synthesis of Klebsiella pneumoniae UVHC5, Escherichia coli ATCC 8739 and Pseudomonas jessinii UVKS19) was investigated. UV-Vis spectroscopy, DLS, SEM and EDX spectroscopy were used to verify the particles formed. Culture media, bacterial supernatants and the individual medium components were added to AgNO3 solutions. After 7 days of incubation the liquids contained particles of different shapes, sizes and composition. The formation of specific particle species mainly depended on the composition of the culture media (especially the Cl- content), in which the bacteria were inoculated. Samples incubated with bacterial supernatant of STI, NB, LB or MH showed AgCl particles of cubic or star-/flowerlike shapes coated with AgNPs. In contrast, silver nanoclusters were observed in the inoculants of bacterial supernatants grown in MRS or AgNPNB. However, small effects of bacterial metabolites on the formation of the particles could be observed and indicate an influence of the media alteration by bacterial growth on the particle formation. When the individual medium components were added to AgNO3, different absorbance spectra were obtained. Therefore, we conclude that the formation of Ag/AgCl nanoparticles results from the interaction of all medium components.

Phosphorus is an important macronutrient, but its availability in soil is limited. Many soil microorganisms improve the bioavailability of phosphate by releasing it from various organic compounds, including phytate. To investigate the diversity of phytate-hydrolyzing bacteria in soil, we sampled soils of various ecological habitats, including forest, private homesteads, large agricultural complexes, and urban landscapes. Bacterial isolate Pantoea sp. strain 3.5.1 with the highest level of phytase activity was isolated from forest soil and investigated further. The Pantoea sp. 3.5.1 agpP gene encoding a novel glucose-1-phosphatase with high phytase activity was identified, and the corresponding protein was purified to apparent homogeneity, sequenced by mass spectroscopy, and biochemically characterized. The AgpP enzyme exhibits maximum activity and stability at pH 4.5 and at 37°C. The enzyme belongs to a group of histidine acid phosphatases and has the lowest K m values toward phytate, glucose-6-phosphate, and glucose-1-phosphate. Unexpectedly, stimulation of enzymatic activity by several divalent metal ions was observed for the AgpP enzyme. High-performance liquid chromatography (HPLC) and high-performance ion chromatography (HPIC) analyses of phytate hydrolysis products identify dl - myo -inositol 1,2,4,5,6-pentakisphosphate as the final product of the reaction, indicating that the Pantoea sp. AgpP glucose-1-phosphatase can be classified as a 3-phytase. The identification of the Pantoea sp. AgpP phytase and its unusual regulation by metal ions highlight the remarkable diversity of phosphorus metabolism regulation in soil bacteria. Furthermore, our data indicate that natural forest soils harbor rich reservoirs of novel phytate-hydrolyzing enzymes with unique biochemical features.

Minimally processed fresh-cut (MPFC) fruit products are an important source of functional ingredients, and increased consumers’ demand boosted an expansion of this segment of food industry. Apples (Malus sp.) are commonly cultivated fruits and processed to MPFC products. Their low shelf life is the main obstacle for gaining maximum nutritive and economic benefits. Enzymatic, metabolic, and other physiological processes induce changes that render the product spoiled and decrease the storage and marketability life of MPFC fruits. Such spoilage can be controlled by modified atmosphere packaging (MAP), but intrinsic influences of numerous MAP factors are not clearly elucidated. Microbial growth adds another layer of complexity to MAP. Mathematical modeling can successfully predict microbial growth and spoilage, hence saving production cost and provide better control over the production chain. In this sense, this review provides an overview of MAP’s factors that influence the quality of stored MPFC products. Focus was placed on apples and development of mathematical models that can be useful for prediction of their spoilage during storage and subsequently their shelf-life.

Akara is one of Brazil's national treasures prepared from cowpea (Vigna unguiculata L.Walp), grated onions and salt and deep-fried in crude palm oil. The results of this study on akara preparation methods showed that, in general, cowpeas were soaked for up 3 hours at room temperature, and the seed coats were then removed. The akara makers preferred the olho de pombo cultivar, because of its cream hue, or the macassar cultivar because it produces a crispier paste. The seeds purchased from street markets had lower ranges of InsP6, InsP5, and InsP4 (1.03-7.62 ∝mol.g - 1; 0.14-1.31 ∝mol.g - 1; and 0.0-0.10 ∝mol.g - 1, respectively) than both the paste and akara (6.72-19.24 ∝mol.g - 1; 1.29-4.57 ∝mol.g - 1; 0.0-0.76 ∝mol.g - 1; 3.31-13.71 ∝mol.g - 1; 0.0-4.48 ∝mol.g - 1; and 0.0-1.32 ∝mol.g - 1). These results suggest that other beans or cowpea varieties have been used in the preparation of akara and that the phytate levels do not affect its nutritional quality.

Nanoparticles are ubiquitous in the environment. They originate from anthropogenic or natural sources or they are intentionally produced for different purposes. There exist manifold applications of nanoparticles in modern life leading unavoidably to a confrontation and interaction between nanomaterial and living organisms. Based on their wide distribution tending to increase steadily, the influence of particles based on silica and silver, exhibiting nominal sizes between 0.65 nm and 200 nm, on the physiology of the mycotoxigenic filamentous fungus Penicillium verrucosum was analyzed. The applied concentration and time-point, the size and the chemical composition of the particles was shown to have a strong influence on growth and mycotoxin biosynthesis. On microscopic scale it could be shown that silver nanoparticles attach to the mycelial surface. Moreover, silver nanoparticles with 0.65 nm and 5 nm in size were shown to internalize within the cell, form agglomerates in the cytoplasm and associate to cell organelles.

In this study 97 soil samples from different soil ecosystems were collected. The initial screening was performed on modified glycerol arginine agar (MGAA) to isolate common actinomycetes and on modified MGA-SE (MMGA-SE) to isolate rare actinomycetes. Sixty-seven isolates potentially producing extracellular phytate-degrading activity were identified. The potential to dephosphorylate phytate was confirmed in liquid culture for 46.3 % of the isolates. 12 strains were selected for a direct determination of their phytate-degrading capacity. The results highlighted that the selected isolates produced extracellular phytate-degrading activity; however their capacity in InsP(6) degradation was different. In addition the fermentation medium had an effect on the extent of phytate degradation. Some enzymatic properties of the phytases from isolate No. 43 and isolate No. 63 were determined after obtaining phytase-enriched samples. The enzymes had maximum phytate-degrading capability at 55 °C and pH 5 (isolate No. 43) and 37 °C and pH 7 (isolates No. 63), respectively. Due to their properties, the phytase of isolate No. 43 behaves like a histidine acid phytase, whereas the phytase of No. 63 showed similar enzymatic properties to the phytase of lily. To our knowledge, the results from this study demonstrated for the first time that actinomycetes produce extracellular phytate-degrading activity. By 16SrRNA sequencing, the more closely studied phytase producers were identified as Streptomyces sp. Isolate No. 43 showed 98 % identity to Streptomyces alboniger and S. venezuelae, while isolate No. 63 exhibited 98 % sequence identity to S. ambofaciens and S. lienomycini.

Citric pulp is an agro-industrial residue from the citrus processing industry with low inorganic phosphorus content applied in animal feed. A new bioprocess was developed to produce and purify a new phytase generated on citric pulp fermentation by Aspergillus niger FS3. The phytase was purified by cationic-exchange, anionic-exchange chromatography and chromatofocusing steps. From SDS–PAGE analysis, the molecular weight of the purified phytase was calculated to be 108 kDa. The phytase had an optimum pH of 5.0–5.5 and an optimum temperature of 60°C. The phytase displayed high affinity for phytate, and the Km was 0.52 mM. The purified phytase was sufficiently able to withstand pelleting temperatures, retaining sufficiently high phytate-degrading activity.

A unique DNA isolation protocol based on microwave irradiation and density centrifugation for the simultaneous detection of porcine, chicken, and mutton meat species in food by PCR using newly developed primers is described. Emphasis is placed on the detection of pork, as it is considered unlawful in the diet in major religions such as Islam and Judaism. The method has been optimized using the primers designed from porcine mitochondrial DNA (mtDNA) sequence and tested in 96 samples. The method involves 35 seconds of high microwave irradiation of lysed sample homogenate followed by a 5- min centrifugation in 1.5 mL Eppendorf tubes until a clear supernatant is obtained. The design of this protocol makes it possible to process many samples in a short time. To evaluate the method pork and food spiked with different concentrations of pork together with unknown food samples were analyzed by PCR using the new set of porcine specific primers. The new set of primers and the method involved showed high sensitivity ...

The aim of this study was to verify the effects of gamma radiation process on the fungal DNA and the application of PCR in the detection of Aspergillus flavus in irradiated maize grains. The samples were inoculated with a toxigenic strain and incubated under controlled conditions of relative humidity, water activity, and temperature for 15 days. After incubation, the samples were treated with gamma radiation with doses of 5 and 10 kGy and individually analyzed. The use of PCR technique showed the presence of DNA bands of Aspergillus flavus in all irradiated samples that showed no fungal growth in agar medium.

Qualitative and quantitative polymerase chain reaction-based methods to detect genetically modified soy (RoundupReady™ soy) and maize (Bt176 Maximizer™ maize, Bt11 maize, MON810 YieldGard™ corn, T25 LibertyLink™ maize) were applied to processed foods sold commercially in Brazil. From 2000 to 2005, 100 food products containing maize and 100 food products containing soy were analysed every single year. The presence of genetically modified soy increased steadily from 13% in 2000 to 78% in 2005. The number of food products containing genetically modified soy in a proportion above 1.0% on the ingredient level, the threshold for labelling according to Brazilian legislation, increased from 11% in 2000 to 36% in 2005. No clear trend was found within maize containing food products. Eight to eleven percent were shown to consist of material derived from genetically modified maize and 4–6% were found to contain more than 1% of genetically modified maize.

Over two hundred bacteria were isolated from the halosphere, rhizosphere and endophyte of Malaysian maize plantation and screened for phytases activity. Thirty isolates with high detectable phytase activity were chosen for media optimization study and species identification. Ten types of bacterial phytase producers have been discovered in this study, which provides opportunity for characterization of new phytase(s) and various commercial and environmental applications. The majority of the bacterial isolates with high detectable phytase activity were of endophyte origin and 1.6% of the total isolates showed phytase activity of more than 1 U/ml. Most of the strains produced extra-cellular phytase and Staphylococcus lentus ASUIA 279 showed the highest phytase activity of 1.913 U/ml. All 30 species used in media optimization study exhibit favorable enzyme production when 1% rice bran was included in the growth media.

Feed is the foremost and highest expense in large-scale breeding of monogastric animals, accounting for more than 70% of the total production costs. For more than 30 years, various enzymes have been used to improve the efficiency of feedstuff utilization. These enzymes are applied to simultaneously address many different practical problems in feed use, such as reducing the presence of antinutritional factors, increasing the digestibility of feed constituents, reducing the viscosity in the digestive tract, allowing the use of low-cost ingredients, and reducing environmental risks related to manure and waste disposal. The main feed enzymes in the market are phytases, xylanases and β-glucanases (cellulases). Nevertheless, other enzymes, such as mannanases, α-galactosidases, pectinases, amylases and proteases, are increasing in use. Poultry and swine sectors are the main feed enzyme consumers; however, ruminants, aquaculture and pets are projected to be large markets in the near future. Recent and future advancements in this field of knowledge are discussed here.

Qualitative and quantitative polymerase-chain-reaction-based methods to detect genetically modified (gm) soy (RoundupReadyTM soy) and maize (Bt176 Maximizer maize; Bt11 maize, MON810 Yield Gard corn, T25 LibertyR Link maize) were applied to processed foods sold commercially in Brazil. In total 100 foods containing maize and 100 foods containing soy were analysed in 2000 and again in 2001. In 2000, 13% of the soy containing products and 8% of those containing maize were shown to consist of material derived from the corresponding genetically modified organisms. In five samples of the products containing gm soy 4% of the soy derived material was identified as coming from gm soybeans, whereas in the case of products containing gm maize five samples of the maize derived material were found to contain 4% of gm maize. In 2001, gm soy was found in 21% of the soy containing foods, and gm maize was found in 9% of the maize containing products. Eight samples of the products containing gm soy were shown to contain 4% of gm soy, the corresponding values for gm maize were five samples 4%.

Modern sugarcane cultivars have complex genetic characteristics and low fertility that render their genetic improvement through traditional breeding difficult. Genetic engineering methodology to introduce foreign genes provides new opportunities for the genetic improvement of sugarcane cultivars. One of prerequisites for successful insertion of a gene cassette into the plant genome is the availability of an efficient transformation protocol. An improved protocol for Agrobacterium-mediated transformation of sugarcane is described. Between 85 and 100% of calli transformed using this procedure produced new calli, and 100% of them were positive for the inserted gene. The whole procedure permitted the production of transgenic calli in a short time (1.5 mo). The transformed calli can be cultured further for the production of the inserted gene-encoded enzyme by using cell culture, or they can be regenerated into transgenic plants. This protocol may be implemented also for the generation of transgenic plants from other species.

The development of engineered nanometre sized materials (ENM) produced with food-grade ingredients and designed as delivery systems for organic and inorganic materials has gained increasing interest. The major reason for this trend is the aim to overcome problems associated with the low bioavailability of many bioactive compounds (BC) which are usually claimed to benefit human health. In this review, outcomes of studies investigating the potential bioavailability enhancement of BC using ENM as delivery systems are summarised and discussed. It focuses on in vitro and in vivo studies carried out with ENM produced with food-grade materials and designed for the delivery of vitamins, other secondary plant metabolites and minerals. Furthermore, the physical and physicochemical aspects governing the preparation of the systems, the loading of the BC, the stability of the delivery systems in food applications and finally the release of the BC in the gastrointestinal tract are also considered. The mechanisms leading to an enhanced bioavailability are based on (i) improved solubility of the BC under gastrointestinal conditions, (ii) the protection of the BC from the chemical conditions in the gastrointestinal tract (GIT), (iii) the controlled release within the GIT or (iv) an improved transfer through the intestinal wall. The main outcome of the review is that particle size, surface properties and physical state of the ENM are key parameters to be controlled aiming at an enhanced nutritional value of food materials. Furthermore, the bioavailability classification scheme (BCS) can help to understand the efficacy of different ENM for the delivery of specific BC.

Paraquat is a fast acting nonselective contact herbicide that is extensively used worldwide. However, the aqueous solubility and soil sorption of this compound can cause problems of toxicity in nontarget organisms. This work investigates the preparation and characterization of nanoparticles composed of chitosan and sodium tripolyphosphate (TPP) to produce an efficient herbicidal formulation that was less toxic and could be used for safer control of weeds in agriculture. The toxicities of the formulations were evaluated using cell culture viability assays and the Allium cepa chromosome aberration test. The herbicidal activity was investigated in cultivations of maize (Zea mays) and mustard (Brassica sp.), and soil sorption of the nanoencapsulated herbicide was measured. The efficiency association of paraquat with the nanoparticles was 62.6 ± 0.7%. Encapsulation of the herbicide resulted in changes in its diffusion and release as well as its sorption by soil. Cytotoxicity and genotoxicity assays showed that the nanoencapsulated herbicide was less toxic than the pure compound, indicating its potential to control weeds while at the same time reducing environmental impacts. Measurements of herbicidal activity showed that the effectiveness of paraquat was preserved after encapsulation. It was concluded that the encapsulation of paraquat in nanoparticles can provide a useful means of reducing adverse impacts on human health and the environment, and that the formulation therefore has potential for use in agriculture.

Using a combination of high-performance ion chromatography analysis and kinetic studies, the stereospecificity of myo -inositol hexakisphosphate dephosphorylation by the phytate-degrading enzyme P2 of Escherichia coli was established. High-performance ion chromatography revealed that the phytate-degrading enzyme P2 of E. coli degrades myo -inositol hexakisphosphate by stepwise dephosphorylation via d / l -Ins(1,2,3,4,5)P 5 , d / l -Ins(2,3,4,5)P 4 , d / l -Ins(2,4,5)P 3 or d / l -Ins(1,2,4)P 3 , d / l -Ins(1,2)P 2 or Ins(2,5)P 2 or d / l -Ins(4,5)P 2 to finally Ins(2)P or Ins(5)P. Kinetic parameters for myo -inositol pentakisphosphate hydrolysis by E. coli and wheat phytase, respectively, showed that the myo -inositol pentakisphosphate intermediate produced either by the phytate-degrading enzyme of wheat or E. coli are not identical. The absolute configuration of the myo -inositol pentakisphosphate isomer produced by the E. coli enzyme was determined by taking into consideration that wheat phytase produces predominantly the d -Ins(1,2,3,5,6)P 5 isomer (Lim, P.E., Tate, M.E., 1973. The phytases: II. Properties of phytase fraction F 1 and F 2 from wheat bran and the myo -inositol phosphates produced by fraction F 2 . Biochim. Biophys. Acta 302, 326–328). The data demonstrate that the phytate-degrading enzyme P2 of E. coli dephosphorylates myo -inositol hexakisphosphate in a stereospecific way by sequential removal of phosphate groups via d -Ins(1,2,3,4,5)P 5 , d -Ins(2,3,4,5)P 4 , d -Ins(2,4,5)P 3 , Ins(2,5)P 2 to finally Ins(2)P (notation 6/1/3/4/5).

A phytate-degrading enzyme (myo-inositol hexakisphosphate phosphohydrolase) has been purified about 5,400-fold from germinated oat seedlings to apparent homogeneity. The molecular mass of the native monomeric enzyme was estimated to be about 67 kDa. Optimal pH for degradation of phytate was 5.0 and the optimal temperature 38 °C. Kinetic parameters for the hydrolysis of Na-phytate are KM 30 µM and kcat 356 s−1 at 35 °C and pH 5.0. The oat phytase exhibits a broad affinity for various phosphorylated compounds and hydrolyses phytate in a stepwise manner. The first hydrolysis product was identified as D/L-l(1,2,3,4,5) P5. © 1999 Society of Chemical Industry

Model systems for investigating the influence of the food matrix and depth of processing on detection limits for foods deriving from genetic engineering were established using the phytase-encoding gene ofEscherichia coliATCC 33965. For detection the polymerase chain reaction was applied directly to DNA extracted from foods based on cereals.E. colicells andE. coliDNA were added to musli, rolled oats, and rye flour in concentrations of 1010to 102CFU and 10 mg to 10 pg per gram, respectively. After soaking of the food samples in water or yoghurt, detection limits were determined to be 103to 104CFU and 10 to 100 pg by specific DNA hybridization. After sourdough fermentation of rye flour a hybridization signal was observed only with rather highE. coliconcentrations (>1010CFU), whereas detection was impossible in ready-baked breads.

Inositol polyphosphatases (IPPases), particularly those that can hydrolyze myo-inositol hexakisphosphate (Ins P(6)), are of biotechnological interest for their ability to reduce the metabolically unavailable organic phosphate content of feedstuffs and to produce lower inositol polyphosphates (IPPs) for research and pharmaceutical applications. Here, the gene coding for a new protein tyrosine phosphatase (PTP)-like IPPase was cloned from Megasphaera elsdenii (phyAme), and the biochemical properties of the recombinant protein were determined. The deduced amino acid sequence of PhyAme is similar to known PTP-like IPPases (29-44% identity), and the recombinant enzyme displayed strict specificity for IPP substrates. Optimal IPPase activity was displayed at an ionic strength of 250 mM, a pH of 5.0, and a temperature of 60 degrees C. In order to elucidate its stereospecificity of Ins P(6) dephosphorylation, a combination of high-performance ion-pair chromatography and kinetic studies was conducted. PhyAme displayed a stereospecificity that is unique among enzymes belonging to this class in that it preferentially cleaved Ins P(6) at one of two phosphate positions, 1D-3 or 1D-4. PhyAme followed two distinct and specific routes of hydrolysis, predominantly degrading Ins P(6) to Ins(2)P via: (a) 1D-Ins(1,2,4,5,6)P(5), 1D-Ins(1,2,5,6)P(4), 1D-Ins(1,2,6)P(3), and 1D-Ins(1,2)P(2) (60%) and (b) 1D-Ins(1,2,3,5,6)P(5), 1D-Ins(1,2,3,6)P(4), Ins(1,2,3)P(3), and D/L-Ins(1,2)P(2)(35%).

It is estimated that 25 to 50% of the crops harvested worldwide are contaminated with mycotoxins. Because of the toxic and carcinogenic potential of mycotoxins, there is an urgent need to develop detection methods that are rapid and highly specific. The highly advanced physico-chemical methods for the analysis of mycotoxins in use, have the disadvantage that highly sophisticated clean-up and/or derivatization procedures must be applied. An alternative could be the detection of the mycotoxigenic moulds themselves, especially as molecular techniques have been introduced recently as powerful tools for detecting and identifying fungi. PCR methods for the detection of aflatoxigenic Aspergilli, patulin-producing Penicillum and trichothecene- as well as fumonisin-producing Fusaria strains have been described. The usefulness of the PCR methods developed so far to monitor quality and safety in the food an feed industry was already demonstrated. Thus, PCR may be applied to the screening of agricultural commodities for the absence of mycotoxin producers prior to or even after processing. Negative results in this assay indicate that a sample should be virtually free of mycotoxins. Only the positive samples left must be analyzed for the presence of mycotoxins using physico-chemical standard methods. This review does not only summarize the so far developed qualitative and quantitative PCR assays for the detection of mycotoxigenic fungi in agricultural commodities, foods and animal feeds, but describes also strategies to develop new specific PCR assays for such a detection.

Klebsiella sp. strain ASR1 isolated from an Indonesian rice field is able to hydrolyse myo-inositol hexakis phosphate (phytate). The phytase protein was purified and characterised as a 42 kDa protein accepting phytate, NADP and sugar phosphates as substrates. The corresponding gene (phyK) was cloned from chromosomal DNA using a combined approach of protein and genome analysis, and expressed in Escherichia coli. The recombinant enzyme was identified as a 3-phytase yielding myo-inositol monophosphate, Ins(2)P, as the final product of enzymatic phytate hydrolysis. Based on its amino acid sequence, PhyK appears to be a member of a hitherto unknown subfamily of histidine acid phytate-degrading enzymes with the active site RHGXRXP and HD sequence motifs, and is different from other general phosphatases and phytases. Due to its ability to degrade sodium phytate to the mono phosphate ester, the phyK gene product is an interesting candidate for industrial and agricultural applications to make phytate phosphorous available for plant and animal nutrition.